Effect of alloy grain size on the high-temperature oxidation behavior of the austenitic steel TP 347



Título del documento: Effect of alloy grain size on the high-temperature oxidation behavior of the austenitic steel TP 347
Revista: Materials research
Base de datos: PERIÓDICA
Número de sistema: 000312841
ISSN: 1516-1439
Autores: 1



Instituciones: 1University of Siegen, Institute of Material Science, Siegen, Nordrhein-Westfalen. Alemania
Año:
Periodo: Oct-Dic
Volumen: 8
Número: 4
Paginación: 371-375
País: Brasil
Idioma: Inglés
Tipo de documento: Nota breve o noticia
Enfoque: Experimental
Resumen en inglés Generally, oxide scales formed on high Cr steels are multi-layered and the kinetics are strongly influenced by the alloy grain boundaries. In the present study, the oxidation behaviour of an austenite steel TP347 with different grain sizes was studied to identify the role of grain-boundaries in the oxidation process. Heat treatment in an inert gas atmosphere at 1050 °C was applied to modify the grain size of the steel TP347. The mass gain during subsequent oxidation was measured using a microbalance with a resolution of 10-5 g. The scale morphology was examined using SEM in combination with energy-dispersive X-ray spectroscopy (EDS). Oxidation of TP347 with a grain size of 4 µm at 750 °C in air follows a parabolic rate law. For a larger grain size (65 µm), complex kinetics is observed with a fast initial oxidation followed by several different parabolic oxidation stages. SEM examinations indicated that the scale formed on specimens with smaller grain size was predominantly Cr2O3, with some FeCr2O4 at localized sites. For specimens with larger grain size the main oxide is iron oxide. It can be concluded that protective Cr2O3 formation is promoted by a high density of fast grain-boundary diffusion paths which is the case for fine-grained materials
Disciplinas: Ingeniería
Palabras clave: Ingeniería de materiales,
Ingeniería metalúrgica,
Acero,
Aleaciones,
Oxidación,
Alta temperatura,
Granos
Keyword: Engineering,
Materials engineering,
Metallurgical engineering,
Steel,
Alloys,
Oxidation,
High temperature,
Grains
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